European activities in the field of high energy neutron dosimetry as applied to fusion devices and spallation sources are outlined. The present status of the related neutron cross-section data is described, and the need for further work is considered. The survey concentrates on three topics: (1) measurements of neutron spectra and fluences for spallation neutron sources, (2) application of nuclear diagnostic techniques at experimental Tokamak devices, and (3) construction of neutron cross-section libraries for energies of up to 1 GeV.